Here is a word root worksheet on the Greek word root kilo–, which means thousand. This turns up all over the place in English, particularly in metric measurements like kilometer and kiloton. I expect this is a word root students should know for work in the hard sciences–even in a high school classroom.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.